Insmed claims first human study showing "biosimilar" bioequivalence to Neupogen

US biopharmaceuticals firm Insmed has demonstrated the bioequivalence of INS-19, its recombinant human granulocyte colony stimulating factor, compared to Amgen's Neupogen (filgrastim), a US-approved G-CSF product for the treatment of neutropenia that earned $1.0 billion last year.

According to the Virginia-headquartered firm, the G-CSF concentration profiles for the two products were identical. Absolute neutrophil count, the primary pharmacodynamic marker for G-CSF products, exhibited the same response profile to dosing with INS-19 as with Neupogen. Insmed says these human data complement its analytical testing and comparative findings from preclinical assessments.

The company intends to request a meeting with the FDA to discuss potentially initiating a Phase III trial program for INS-19. On the day results from the bioequivalance study were released, July 10, Insmed shares rose 15% to $0.46, while Amgen stock increased 1.7% to $51.69.